This proposal continues ongoing research investigating drug effects on human performance and social behavior, extending current residential laboratory procedures to problems related to the use of drugs in the workplace. The residential laboratory provides a unique opportunity to investigate drug effects on multiple dimensions of human behavior that are both directly applicable to the workplace and differentially sensitive to a variety of pharmacological agents under conditions that closely approximate the environmental context of the workplace. Three issues of critical importance to workplace policy will be addressed. First, a comprehensive determination of drug effects on workplace-relevant behavior will be completed. Both the acute and chronic effects of commonly used drugs (marijuana, amphetamine, caffeine, alcohol, triazolam and alprazolam) on multiple human behaviors that are required for workplace productivity and safety will be assessed. In addition, the residual next day, or "hang over", effects of drug use during non-work time will be analyzed. Finally, the effects of drug abstinence, in daily users, on workplace performance must be addressed. Second, the reliability and validity of techniques used to detect drug use in the workplace will be determined. Concurrent with the determination of drug effects on workplace-relevant behavior, both urinalysis and testing with short-term performance batteries designed for the detection of performance impairment will be conducted. The results of these tests will be correlated with the effects of drugs on workplace- relevant behaviors to determine the accuracy and discriminability of these instruments. Third, the relationship between work-related behavioral contingencies and the self-administration of drugs will be measured. The extent to which subjects are held accountable for their daily work efficiency will be manipulated by changing accuracy and speed requirements during work periods. The effects of changes in work requirements on drug self-administration between daily work shifts and during lunch breaks will be determined. The results of these studies will have critical importance for establishment of drug policy in the workplace and for the development of national strategies for reducing drug use.